Tidal flushing system



Feb 3, 1970 w. J. JOSEPHS TIDAL FLUSHING SYSTEM Filed Oct. 26, 1967 Mu xn ma;

wz od a @253 mhiw zmas INVENTOR- Walter J. Josephs BY Attornegs UnitedStates Patent O ice 3,492,822 TIDAL FLUSHING SYSTEM Walter J. Josephs,1924 Courtland Ave., Oakland, Calif. 94601 Filed Oct. 26, 1967, Ser. No.678,440 Int. Cl. E021! 3/00 US. Cl. 611 8 Claims ABSTRACT OF THEDISCLOSURE A system for the environmental improvement of a bay orsimilar body of water subject to tidal flow. The system includes acirculation channel extending along the periphery of the bay, with thechannel having controllable gates, permitting selective ingress andegress of water to and from the channel. At high tide, for example,water may enter the channel adjacent the closed end of the bay, passthrough the channel, and be discharged at the open end of the bay whenthe water level between the channel and this latter portion of the baypermits such egress. Conversely, water can be accumulated in the channelat high tide at the closed end of the bay and discharged through thesame gates at the closed end of the bay at low tide.

In the first instance, improved circulation of the water in the bay willresult, and in the second instance, buildup of sand or silt due toincoming tides are pushed back, and a harbor mouth, for example, may bekept open for shipping.

Background of the invention In many instances bays or like bodies ofwater be come polluted and stagnate, notwithstanding their beingsubjected to ocean tides. A typical example of such a problem is foundparticularly in the southern portion of the San Francisco Bay. This bayis relatively long and narrow, and although it is in direct flowcommunication with the Pacific Ocean through the Golden Gate, there isin fact no effective circulation of water particularly at the southernor closed end of the bay, even though the tides are greater at thisportion of bay than at the Golden Gate where clean ocean water regularlyenters the bay at high tide. Due to a number of factors, including thetime lapse between high tide at the entry to the bay and high tide atthe closed end of the bay, there is no appropriate flushing action.Instead, there is only what might be termed a standing wave of stalewater which sloshes about, without mixing with the clean ocean water.

Another problem frequently encountered is that of flood waters resultingfrom rain swollen creeks or streams which discharge into the bay. Athigh tide particularly, such tributaries will overflow and createsubstantial problems to the adjacent land masses.

It should be made clear at the outset, that while the particular bay andenvironment is indicative of San Francisco Bay, the present invention isnot intended to be limited thereto, but rather to the general conceptshereinafter set forth in the claims.

Summary of the invention In broad terms, the present invention isdirected to the use of a man-made channel extending around the bay inthe general shape of a horseshoe. One or more intake control gates areprovided along the channel, and the end portions are provided withoutfall or discharge gates. The gates may be opened and closed in anyconventional manner including the use of differential water pressure orlevel between the adjacent bay water and the water in the channel.

3,492,822 Patented Feb. 3, 1970 In order to provide for the flushingaction water would be permitted to enter the channel through the intakegates at high tide. Such water would flow through the channel towardsits ends, and at low tide the outfall ates, would be opened, allowingthe water in the channel to enter the bay and be sucked out to sea.

The invention further contemplates the use of the channel and gates forflood control, cleaning silt or sand from an inlet, and cleansing of thechannel itself.

Also, there is embraced in this disclosure the use of artificial orman-made islands in a bay to assist in elfecting circulation, agitationand flushing of otherwise stagnant water.

Brief description of the drawings FIGURE 1 is a plan view, somewhatdiagrammatic in character, illustrating a bay employing the system ofthe invention.

FIGURE 2 is a profile chart illustrating the operation of the systemrelative to tide conditions.

Description of the preferred embodiment As hereinabove suggested, thedrawing is generally representative of the southern portion of SanFrancisco Bay wherein the pollution problem is particularly acute,especially at the closed end portion 6 of the bay. In fact this portionis at the southern end of the bay, rather than at the eastern end asmight appear from the drawing. The normal tidal flow at the open endportion 7 of the bay is bidirectional as illustrated at 8, such portionbeing in communication with the Golden Gate, which is to the left ofportion 7, but not shown in the drawing.

As above mentioned, at the portion 7, the tidal flow goes in bothdirections, i.e., to the right at high tide, and a discharge to the leftat ebbing or low tide. However, the closer one approaches to the closedend of the bay, there is no substantial flow or discharge to the leftsince by the time the high tide reaches portion 6, the differentialheight differential between portions 6 and 7 is insufiicient to permitproper reverse flow and resulting scavenging or cleansing of thechannel.

It should also be pointed out that a number of streams, sloughs, creeks,etc., generally designated by the numeral 9, empty into the bay andcreate some of the problems above mentioned.

In accordance with the teachings of the present invention, all of theabove and other problems normally encountered in this type of bayarrangement are overcome, by first providing a man-made channel 12extending longitudinally of the bay and which as here shown generallyfollows the peripheral shore line of the bay. The channel is ofgenerally horseshoe configuration including sides 13 and 14, a loop 16adjacent the closed bay portion 6, and ends 17 and 18, adjacent the bayinlet 7. The inner and outer channel walls 21 and 22 are suflicientlyhigh so that water from the bay will not overflow into the channel, evenat high tide. It will also be noted that the outer Wall of the channelhas openings in alignment with the tributaries 9 so that run-off fromthe latter is directed into channel 12 rather than into the bay. Ifdesired, ship locks 23 may be provided at convenient locations along thechannel so as to permit passage of ships between the bay and thetributaries, irrespective of water level differentials.

As an important feature of this invention, a plurality of intake controlgates are provided in channel wall 21. Such gates may be normallyclosed, but when the tide is coming in to the bay, such gates may beopened to permit the incoming tide waters to pass through the gates andenter the channel 12. Preferably, one or more gates 31 are provided atthe channel loop 16 with additional gates 32 provided along the channelsides. These gates may be of conventional design and construction andperable in the normal manner for large hydraulic gate members.

At the channel ends 17 and 18, outfall gates 33 are provided generallysimilar in construction and operation to gates 31 and 32.

In a typical operation for such a system, first assume that all gatesare closed and the channel empty of water. As the tide enters the bay,the intake gates 31, and possibly 32 are opened to an extent wherein thewater level in the bay exceeds the gate height, so that Water rushesinto the channel adjacent the closed end of the bay and will naturallyseek its own level throughout the entire length of the channel. Thislevel will correspond to the high tide level of the bay portion 6. Then,when the tide ebbs at the open bay portion 7 to a degree wherein theWater in the channel is higher than the water level at such open bayportion, the outfall gates 33 may be opened, and the water in thechannel will rush into the bay and be carried out to the ocean by theebbing tide. The foregoing will result in a scavenging and propercirculation of the bay waters.

primarily by way of example and not limiting, other than by the scope ofthe following claims.

What is claimed is:

1. A method of flushing a body of water having a generally continuousshore line and an inlet to such body subjected to tidal flow, whichcomprises the steps of providing a channel extending from adjacent saidinlet towards the other end of said body of water, providing selectivelyoperable gates adjacent opposite ends of said channel with a first gateadjacent said inlet and a second gate adjacent said other end of saidbody of water, opening said second gate during high tide in said body ofwater permitting the tide to force water from said body of water throughsaid second gate and into said channel, and then opening said first gateupon ebb tide in said body of water whereby collected water in saidchannel will be discharged from said channel adjacent said inlet to movewith the receding ebb tide.

The channel 12 may likewise be expeditiously utilized for flood control.In the event of excessive rainfall or other conditions leading to anoverflowing of the tributaries 9, the intake gates 31 and 32 may remainclosed during one or more tides so that the streams, etc. may

discharge into the channel, and the water subsequently dischargedthrough gates 33 during ebb tide at bay portion 7.

A further manner in which the channel and gate arrangement can be usedis to accumulate and hold water in the channel and permit the same toescape through the normal intake gates when the water in the bayadjacent such gates is at low tide. Such water action will serve toforce silt, sand, etc. away from the closed end of the bay.

To increase the circulation of Water in the bay, there is also disclosedone or more islands or land masses 41 in the bay having both convex andconcave shore lines on both sides thereof. Such masses will result inthe creation of high velocity areas 42 and 43 on opposed sides of themass 41 and a turbulent vortex zone 44 downstream of the mass.

The above system also provides for and perm-its creation of boat harbors51, swimming and recreation areas 52, etc., but since such particularbenefits do not constitute a part of this invention, no furtherdiscussion is deemed necessary.

FIGURE 2 is a profile, illustrative of the operation of the channelsystem. The bottom horizontal dashed line 56 represents an arbitrarydatum line of zero elevation, with line 57 corresponding to the mean lowtide, it being noted that in San Francisco Bay the latter is higher byabout 0.1 foot at the bay portion 6 than at the Golden Gate. Thisdifferential is accentuated when the mean high tide line 58 is examined,the height of the tide being about 6.7 feet, indicated by vertical line59 at the Golden Gate,

2. A method as set forth in claim 1 including closing said second gateprior to the opening of said first gate;

3. A method as set forth in claim 1 including closing said first gate atabout the time that there is a reversal of tide invsaid body of wateradjacent said first gate from a receding ebb tide to an incoming hightide.

4. A method as set forth in claim 1 including closing said second gateat about the time that there is a reversal of tide in said body of wateradjacent said second gate from an incoming high tide to a receding ebbtide.

5. A method as set forth in claim -1 and further pro-' viding saidchannel with a generally U-shaped configuration with the terminal endsthereof on opposed portions of and adjacent said inlet.

6. A method as set forth in claim 1 wherein said body of water hasopposed shore portions between said inlet and said other end includingthe step of providing an island in said body of Water in spaced relationto said opposed shore portions thereof to provide restricted pass-' agesinterconnecting said inlet and said other end of said body of Watercreating upon an incoming high tide a high velocity water flow throughsaid passages and a turbulent vortex zone intermediate said island andsaid other end of said body of water.

7. A method as set forth in claim 1 including the step of divertingtributary run-off, which naturally empties into said body of Water, fordischarge directly into said channel.

8. A method of flushing a body of Water having agenerally continuousshore line and an inlet to such body subjected to tidal flow, includingthe steps of providing a channel extending from adjacent said inlettowards the other end of said body of water, providing gates selectivelyoperable independent of fluid flow adjacent opposite ends of saidchannel with a first gate adjacent said and about 10 feet, indicated byline 61, at the southerly I closed end of the bay and the intake gate31. The height, represented by line 62, is about 7.6 feet adjacent thebay opening 7 and the outfall gates, and as indicated by line 63, isabout 9.4 feet at the intake gates 32. It will be appreciated that evenif there is no differential in tide heights between the bay portions 7and 6, or if the differential is opposite to that above mentioned, thesystem will nevertheless be operable.

From this profile, the high and lowwater levels in the channels may bedetermined, as well as the excess tide or water available for ingressthrough the channel gates 31 and 32 and circulation and dischargethrough gate 33.

It is intended that the foregoing description will be inlet and a secondgate adjacent said other end ofsaid body of water, opening one of saidgates and closing the other of said gates at about the time that thereis a re versal of tide in said body of water from a receding ebb tide toanincoming high tide, and opening the'other of said gates and closingsaid one of said gatesat about the time that there is a reversal of tidein said body of water from an incoming high tide to a receding ebb tide.

References Cited UNITED STATES PATENTS 299,559 6/1884 Loretz 612 833,54310/1906 Parker 611 2,566,447 9/1951 Griswold 61-20 x FOREIGN PATENTS23,118 1893 Great Britain.

PETER M. CAUN, Primary Examiner

